Citrix and Intel go to bare metal to virtualize PCs

Intel and hypervisor provider Citrix Systems are announcing a joint collaboration that will see a bare-metal hypervisor based on the commercial variant of the Xen hypervisor delivered later this year.

While there are a number of different ways that you can use hypervisors to virtualize your x86 or x64 desktop or laptop computer these days, they all employ what is called a type 2 hypervisor instead of the more robust and secure type 1, or bare metal, hypervisor.

There are lots of ways to give end users a virtual PC, but running a bare-metal hypervisor and its operating systems locally on the machine is the way that companies are probably going to be most comfortable doing it. VMware's Workstation (and its Fusion variant for the Mac), Microsoft's Virtual PC, Parallels' Desktop and Workstation, and Sun's VirtualBox (from the Innotek acquisition), and a number of others all work by loading a hypervisor on top of an operating system and then allowing multiple operating systems to pile into virtual machines running atop the hypervisor.

The underlying operating system - usually Windows, Linux or Mac OS on x64 PCs - provides system services to the VMs, and is a single point of failure and a potential security risk for the virtualized environments. Moreover, operating systems running inside type 2 hypervisors are often clunky and slow.

For security and isolation between VMs, which would allow people to mix personal life and business applications on the same physical machine - something we all do, so don't lie - what you really need is a type 1 hypervisor running on the desktop or laptop machines. So Citrix is teaming up with Intel, which supplies most of the chips used in desktops and laptops, to create a variant of the XenServer hypervisor aimed at PCs.

Under the agreement announced today, the two companies are cooking up a PC hypervisor that will be optimized for Intel's VPro business PC designs and the latest generations of Core 2 and Centrino 2 laptops, which all have the hardware and BIOS features in place to support a hypervisor being buried in their electronics. Significantly, the way Citrix and Intel are doing this, desktops shipped over the past two years and laptops from the last year or so will be able to make use of the Xen desktop hypervisor, not just new machines that start shipping sometime in the second half of the year when this project gets out product.

While Citrix was fired up to be partnering with Intel, the two companies were a little short on the specifics of the agreement and exactly how the hypervisor would be deployed in desktops and laptops. The PC hypervisor will, of course, exploit the VT hardware features in Intel's x64 chips to goose the performance of the Xen hypervisor. Intel expects that its OEM partners will be able to easily pick up this technology and run with it, so presumably Xen will be stored on an internal flash drive inside a machine, much as it is with modern servers using the embedded versions of hypervisors from VMware and Citrix.

The two companies are particularly interested in letting businesses know that the bare-metal hypervisor they are building will allow for encryption of the data that represents an entire machine - a virtual machine is just a monster file on a disk - and that the Trusted Platform Module electronics on VPro motherboards and the related TXT feature that makes use of it will be used by the hypervisor to do this encryption and to otherwise secure the VMs.

Ian Pratt, Xen project founder and the vice president of advanced product for Citrix' Virtualization and Management Division, says that the agreement between Intel and Citrix is not exclusive, and that there are no specific hooks between the VPro electronics and the modified version of the hypervisor. This means you can expect a similar announcement between Intel and VMware soon, and probably one between Intel and Microsoft in the not-too-distant future.

The future Xen PC hypervisor being developed is distinct from XenDesktop, which is the Citrix product for storing virtualized PC servers back in the data center and streaming them down to thin clients or regular PCs. Intel and Citrix expect to be streaming data between PCs and laptops and corporate data centers, just as with XenDesktop, but this time software will be running locally on the PCs instead of back on the servers. That means applications can make use of local hardware, such as USB devices and graphics cards. ®